/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements. See the NOTICE file distributed with this
 * work for additional information regarding copyright ownership. The ASF
 * licenses this file to You under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 
 * http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 * License for the specific language governing permissions and limitations under
 * the License.
 */

package org.apache.commons.exec;

import org.apache.commons.exec.util.DebugUtils;

import java.io.InputStream;
import java.io.OutputStream;

/**
 * Copies all data from an System.input stream to an output stream of the
 * executed process.
 * 
 * @author mkleint
 */
public class InputStreamPumper implements Runnable {

	public static final int SLEEPING_TIME = 100;

	/** the input stream to pump from */
	private final InputStream is;

	/** the output stream to pmp into */
	private final OutputStream os;

	/** flag to stop the stream pumping */
	private volatile boolean stop;

	/**
	 * Create a new stream pumper.
	 * 
	 * @param is
	 *            input stream to read data from
	 * @param os
	 *            output stream to write data to.
	 */
	public InputStreamPumper(final InputStream is, final OutputStream os) {
		this.is = is;
		this.os = os;
		this.stop = false;
	}

	/**
	 * Copies data from the input stream to the output stream. Terminates as
	 * soon as the input stream is closed or an error occurs.
	 */
	public void run() {
		try {
			while (!stop) {
				while (is.available() > 0 && !stop) {
					os.write(is.read());
				}
				os.flush();
				Thread.sleep(SLEEPING_TIME);
			}
		} catch (Exception e) {
			String msg = "Got exception while reading/writing the stream";
			DebugUtils.handleException(msg, e);
		} finally {
		}
	}

	public void stopProcessing() {
		stop = true;
	}

}
